JP3167799B2 - Online handwritten character recognition device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-line handwritten character recognition apparatus for recognizing characters input by handwriting and supporting work such as document creation.

[0002]

2. Description of the Related Art In recent years, an online handwritten character recognition device that recognizes a character input by handwriting via a coordinate input device such as a tablet and provides the recognition result to a document or the like has attracted attention. In this online handwritten character recognition device, the following procedure is required when a new character string is inserted later into an already input sentence.

(1) The function of the apparatus is set to the insertion mode by button operation or the like. (2) The insertion position of the character string is specified by button operation or the like. (3) The character string to be inserted is handwritten on the coordinate input device.

As described above, in the procedure for inserting a character string, the button operations (1) and (2), which are not directly related to the original writing operation, are required. Is a burden on the writer and hinders the scribe's thinking.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and eliminates a button operation for switching to an insertion mode and designating an insertion position in a character string insertion operation. It is an object of the present invention to provide an online handwritten character recognition device capable of inserting a character or a character string without disturbing a writer's thinking.

[0006]

In order to achieve the above object, a handwritten character recognition apparatus according to the present invention includes a coordinate input device for detecting coordinates indicated by a pen-shaped pointing device on a screen of a display device. In an online handwritten character recognition device configured to overlap and recognize a character input by handwriting on the coordinate input device and displaying a character as a recognition result at a position on the screen corresponding to a handwritten position, Phrase separating means for dividing the obtained character string into a plurality of phrases; storage means for storing the positions between the phrases separated by the phrase separating means; and a character or character string input by handwriting and already displayed as a recognition result. From the positional relationship with the character string, the character or the character string input by handwriting is the insertion character or the character inserted into the character string already displayed as the recognition result. If the unit determines whether the input string, that the handwriting input character or character string is the insertion character or insertion string is determined,
Comparing a specific position defined in the inserted character or the inserted character string with a position between phrases stored in the storage means to detect a position between the specific position and the closest phrase,
Means for inserting the insertion character or the insertion character string between the segments separated by this position.

[0007]

According to the present invention, the character string obtained as a recognition result is divided into a plurality of phrases by the phrase separating means, and the positions between the separated phrases are stored in the storage means. Then, based on the positional relationship between the character or the character string input by handwriting and the character string already displayed as the recognition result, the character or the character string input by handwriting is inserted into the character string already displayed as the recognition result or It is determined whether or not it is an insertion character string. As a result, when it is determined that the character is an insertion character or an insertion character string, the position between the specific position defined in the insertion character or the insertion character string such as the center X coordinate of the first character and the phrase stored in the storage means is determined. With the position of
A position between a specific position of the insertion character or the insertion character string and the nearest clause is detected, and the insertion character or the insertion character string is inserted between the phrases separated by this position.

Therefore, according to the present invention, in the character string insertion operation, the switching to the insertion mode and the button operation for specifying the insertion position, which have been required so far, can be eliminated, and the writer's thinking is not hindered. To insert characters or character strings into

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram for explaining a configuration of an online handwritten character recognition device according to one embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a display-integrated coordinate input device. The display-integrated coordinate input device 1 is configured by overlaying a coordinate input device 1b such as a transparent tablet on a screen of a display device 1a such as a liquid crystal display device. The input to the display-integrated coordinate input device 1 is performed by bringing the tip of a stylus pen 1c, which is a pen-shaped pointing device, into contact with the input surface of the coordinate input device 1b.

Reference numeral 2 denotes a character input unit for inputting a series of coordinate values sent from the coordinate input device 1b as image data of handwritten characters. The character input unit 2 sends the input handwritten character image data to the subsequent data processing system as a recognition target, and also sends the input handwritten character image data to the display device 1a of the display-integrated coordinate input device 1 so that the handwriting of the handwritten character is directly displayed on the screen of the display device 1a. Display above.

Reference numeral 3 denotes a mode determination unit for determining a mode between a normal character input mode and a character insertion mode based on a positional relationship between a character or a character string input by handwriting and a character string already displayed. is there. That is, the mode determination unit 3 sets an outer frame for the character or character string input through the character input unit 2 based on the basic character size, and sets another character within the range of the X coordinate of the outer frame. Or, determine whether the character string exists. If it does not exist, the normal character input mode is determined, and if it exists, the character insertion mode is determined.

Reference numeral 4 denotes a character cutout unit that cuts out image data one character at a time from the character string image data input through the mode determination unit 3.

Reference numeral 5 denotes image data of one character cut out by the character cutout unit 4 and a reference character pattern storage unit 6.
Is a character recognition unit that performs character recognition by collating with reference character patterns stored in advance.

Reference numeral 7 designates a sequence of character code data obtained by the character recognizing unit 5 divided into a plurality of clauses, and each X-interval between the clauses.
This is a phrase separator for obtaining coordinates. The X coordinate between phrases is obtained based on the X coordinate of the outer frame of the character string set by the mode determination unit 3.

8 is the X between the phrases obtained by the phrase separating unit 7.
This is a phrase X-coordinate storage unit that stores coordinates for each line.

Reference numeral 9 denotes the closest approximation by comparing the center X coordinate of the inserted character or the first character of the inserted character string with the X coordinate between phrases stored in the inter-phrase X coordinate storage unit 8 in the character insertion mode. A character string insertion processing unit that inserts an insertion character or an insertion character string between phrases separated by the X coordinate between phrases.

Reference numeral 10 denotes a display control unit for controlling the display of characters on the screen of the display device 1a based on the character code data as the recognition result.

Next, the operation of the online handwritten character recognition device of this embodiment will be described.

FIG. 2 shows an initial screen of the display device 1a before character input. As described above, on the initial screen W, a plurality of lines L1, L2, and L3 are displayed as underlines of lines on which characters are written from the beginning.

First, the user writes a character string on the initial screen W using the stylus pen 1c as shown in FIG. 3, for example. At this time, each coordinate pointed by the stylus pen 1c is detected by the coordinate input device 1b, and a series of coordinate values thus obtained is sent to the display device 1a of the display integrated coordinate input device 1 through the character input unit 2. Thereby, the character string handwritten on the screen of the display device 1a is displayed as handwriting as it is. At the same time, a series of coordinate values is input to the mode determination unit 3 through the character input unit 2. The mode determination unit 3 performs the following processing based on the obtained series of coordinate values. FIG. 4 is a flowchart showing a processing procedure of the mode determination unit 3.

The mode determination section 3 has a writing line counter, detects a line on which a character string is written from a sequence of input coordinate values, and sets the number of this line as a current line number in the writing line counter. (Step 401). At this point, the mode flag is set to "0" indicating the normal character input mode. Next, the mode determination unit 3 sets the outer frame of the input character string from the input coordinate value series (step 4).
02). Here, the outer frame of the character string is set in units of a predefined reference character size. Subsequently, the mode determination unit 3
Is the minimum value Xmax and maximum value Xmin of the X coordinate of the set outer frame
Are obtained (step 403). Then, it is checked whether or not the line number currently set in the writing line counter matches the stored line number for the character string that has already been input (step 404). As a result, if they do not match, the minimum value Xmax of the X coordinate of the outer frame of the current input character string
And the maximum value Xmin and the line number currently set in the writing line counter are stored (step 406). If they match, it is checked whether or not there is an overlap between the X coordinate of the outer frame of the current input character string and the X coordinate of the outer frame of the character string already existing on the same line (step 405). As a result, if there is no overlap, the minimum value Xmax and the maximum value Xmin of the X coordinate of the outer frame of the current input character string and the line number currently set in the writing line counter are stored (step 4).
06). If there is an overlap, the mode flag is set to "1" (step 407). Since the input character string this time is the character string first input for a certain line on the initial screen, the subsequent operation will be described here assuming that step 406 has been executed.

Next, the character cutout unit 4 cuts out image data one character at a time from the series of coordinate values input through the mode determination unit 3 and sends the image data to the character recognition unit 5. Character recognition unit 5
Performs character recognition by comparing the input image data of one character with the reference character pattern stored in the reference character pattern storage unit 6, and sends a series of character code data as a recognition result to the phrase separation unit 7.

As a method of separating and recognizing a character string handwritten on one line, for example, an on-line character recognition of a frameless handwritten character string by the candidate character lattice method (Transactions of the Institute of Electronics, Communication and Communication Engineers, Vol. J68-) D No.4, p765 / 772, 1985) ”.

The phrase separating unit 7 that has obtained the character code data series divides the obtained character string into a plurality of phrases, for example, by referring to a word dictionary (not shown) that stores the word information. X of outer frame set by judgment unit 3
From the coordinates, the minimum X coordinate and the X coordinate of each break position between phrases are obtained, and these are stored in the inter-phrase X coordinate storage unit 8. For example, taking the character string "Currently inputting" in FIG. 3 as an example, as shown in FIG.
Is divided into three phrases "current", "input", and "input". The X coordinates of P1, P2, and P3 are stored in the inter-phrase X coordinate storage unit 8. In the inter-segment X-coordinate storage unit 8, each X-coordinate is stored separately for each row so that it can be searched for each row.

Thereafter, the series of character code data obtained by the character recognition unit 5 is sent to the display control unit 1 via the character string insertion processing unit 9.
0, whereby the character pattern corresponding to the character code data is displayed on the screen of the display device 1a in place of the handwriting. At this time, the character string insertion processing unit 9 does nothing because the mode flag is “0”, that is, the normal character input mode is currently set.

The above is the operation in the normal character input mode. Next, the operation for inserting a character string will be described.

FIG. 6 shows a state in which the inserted character string is handwritten. Now, the user is trying to insert a character string C1 of "handwriting" between each of the clauses of "current" and "input" of the character string C saying "I am currently inputting." At this time, the user performs the handwriting input of the insertion character string C1 such that the position of the first character of the insertion character string C1 overlaps the break position (P1 in this example) between the clauses at the insertion destination in the X coordinate.

The series of coordinate values forming the inserted character string thus input by hand is sent to the display device 1a of the display-integrated coordinate input device 1 through the character input unit 2. Thereby, the inserted character string handwritten on the screen of the display device 1a is displayed as handwriting as it is.

At the same time, the series of coordinate values at this time is input to the mode determination unit 3. As shown in FIG. 4, the mode determination unit 3 detects a line on which a character string is written from a sequence of input coordinate values, and sets the number of this line as a current line number in a writing line counter (step 401). ). Next, the mode determination unit 3 sets the outer frame of the inserted character string (step 402), and obtains the minimum value Xmax and the maximum value Xmin of the X coordinate of the set outer frame (step 403). Then, it is checked whether or not the line number currently set in the writing line counter matches the stored line number for the character string that has already been input (step 404). in this case,
Since it is determined that they match, the mode determination unit 3
Checks whether there is an overlap between the X coordinate of the outer frame of the inserted character string and the X coordinate of the outer frame of the character string already existing on the same line (step 405). As a result, it is determined that there is an overlap, and the mode flag is set to "1" (step 407).

Thereafter, the character cutout unit 4 cuts out image data one character at a time from the series of coordinate values input through the mode determination unit 3 and sends them to the character recognition unit 5.
The character recognition unit 5 performs character recognition on the input character image data, and sends a series of character code data as a recognition result to the character string insertion processing unit 9 via the character separation unit 7.
At this time, the character delimiter 7 sets the mode flag to “1”.
Do nothing by knowing that

FIG. 7 is a flowchart showing the procedure of the process performed by the character string insertion processing section 9. First, the character string insertion processing unit 9 checks the state of the mode flag (step 701). When it is determined that the mode flag is set to "1", the center X coordinate (Xins) of the first character C2 of the insertion character string C1 shown in FIG. 6 is obtained (step 702). Next, the line number indicated by the current writing line counter is checked, and a character string having the same line number among the already input character strings is selected as a character string to be inserted (step 703). Next, the character string insertion processing unit 9 reads out the respective X coordinates of the phrase separation positions P0, P1, and P2 in the selected input character string from the inter-phrase X coordinate storage unit 8 (step 704). Thereafter, the X-coordinate of each of the read segment break positions P0, P1, and P2,
The center X coordinate of the first character of the inserted character string is compared with the center X coordinate, and the X coordinate of the segment break position (P1 in this example) having the minimum distance from the center X coordinate is determined (step 70).
5). Then, as shown in FIG. 8, the inserted character string "handwriting" C1 is inserted between the segments separated at the corresponding segment break positions (step 706). Thereafter, the mode flag is reset to "0" to switch to the normal character input mode (step 707).

Although the case where the character sizes are all the same has been described here, insertion processing can be performed even if characters having different character sizes exist in one line as shown in FIG. This figure shows an example in which only the “current” phrase is set to a double width relative to the basic character size. In this case, the mode determination unit 3 and the character string insertion processing unit 9 determine whether the “current”
After determining that one character has twice the length in the X coordinate axis direction, each process is performed. In addition, the same applies to the case where some characters are half-width or other size.

Thus, according to the on-line handwritten character recognition apparatus of this embodiment, the insertion character or the first character of the insertion character string is positioned so as to be overlapped in the X coordinate with the delimiter between the inserted phrases in the input character string. The insertion process can be performed only by inputting the insertion character or the insertion character string by handwriting. Therefore, it is possible to eliminate operations that are not directly related to the writing operation such as button operation, which has been required in the case of switching to the insertion mode or specifying the insertion position, so that characters or characters can be written without disturbing the writer's thinking. Character strings can be inserted.

As another embodiment of the present invention, the character string after inserting the character string is again divided into a plurality of phrases by the phrase separating section 7, and the X coordinates between the respective phrases are obtained. , The X-coordinate of the corresponding row in the inter-phrase X-coordinate storage unit 8 may be updated. In this way, a character string can be inserted many times into a character string in one line.

In the present embodiment, the center X coordinate of the first character of the inserted character string is compared with the X coordinate between segments. For example, the minimum X coordinate of the first character is set as a comparison target. Which position of the inserted character string is to be compared with the X coordinate between phrases can be freely selected to some extent.

Further, in this embodiment, when an inserted character string is written above an already-input character string in the same line, it is determined whether or not this is an inserted character string. This determination may be made when an insertion character string is written in the.

[0038]

As described above, according to the online handwritten character recognition apparatus of the present invention, a character or character string input by handwriting is replaced by an inserted character or inserted character string with respect to a character string already displayed as a recognition result. It can be automatically determined whether or not there is. If it is determined that the character is an insertion character or an insertion character string, the position between the specific position defined in the insertion character or the insertion character string, for example, the center X coordinate of the first character, and the phrase between the phrases stored in the storage means is determined. Can be compared to detect the position between the specific position of the inserted character or the inserted character string and the closest clause, and the inserted character or the inserted character string can be automatically inserted between the clauses separated by this position . Therefore, according to the present invention, it is possible to eliminate the switching to the insertion mode and the button operation for specifying the insertion position, which have been required in the insertion operation of the character string, so that the character or the character can be written without disturbing the writer's thinking. You can insert columns.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an online handwritten character recognition device according to an embodiment of the present invention.

FIG. 2 is a diagram showing an initial screen of a display device before character input.

FIG. 3 is a diagram illustrating an example in which a character string is input by handwriting on an initial screen.

FIG. 4 is a flowchart illustrating a processing procedure of a mode determination unit in FIG. 1;

FIG. 5 is a diagram showing a state where a character string is divided into a plurality of phrases.

FIG. 6 is a diagram illustrating a state in which an insertion character string is input by handwriting with respect to an existing character string.

FIG. 7 is a flowchart illustrating a procedure of processing of a character string insertion processing unit in FIG. 1;

FIG. 8 is a diagram showing a state in which a character string insertion process has been completed.

FIG. 9 is a diagram for explaining another operation example in the present embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Display integrated type coordinate input device, 1a ... Display device, 1b ...
Coordinate input device, 1c stylus pen, 2 character input unit, 3 mode determination unit, 4 character extraction unit, 5 character recognition unit, 6 reference character pattern storage unit, 7 phrase separation unit, 8 phrase Inter-X coordinate storage unit, 9 ... character string insertion processing unit,
10. Display control unit.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G06K 9/62 G06F 3/03 G06F 17/22-17/24 JICST file (JOIS)

Claims (1)

(57) [Claims] 1. A coordinate input device for detecting coordinates designated by a pen-like pointing device is superimposed on a screen of a display device, and a character input by handwriting input to the coordinate input device is recognized. In an online handwritten character recognition device for displaying a character as a recognition result at a position on the screen corresponding to a handwriting position, a phrase separating means for partitioning a character string obtained as a recognition result into a plurality of phrases; Storage means for storing the position between the sentence segments, and the character or character string input by handwriting is recognized from the positional relationship between the character or character string input by handwriting and the character string already displayed as the recognition result. Means for determining whether the result is an inserted character or an inserted character string for a character string already displayed, and the handwritten input character or When it is determined that the character string is the insertion character or the insertion character string, a specific position determined in the insertion character or the insertion character string is compared with the position between the phrases stored in the storage means. Means for detecting a position between phrases that is closest to the specific position and inserting the inserted character or character string between phrases separated by sandwiching this position. .